Study On Tunnel Luminance Detection System Based On Image Processing

Along with the rapid development of highway in our country, there have been anincreasing number of tunnels are constructed. Tunnel illumination which is differentfrom ordinary road illumination should consider operation cost, safety and comfortdriving. Luminance detection is very improtant for the design and controlling of tunnelillumination system. Existing luminance detection methods no longer meet therequirements of tunnel illumination, thus using scientific methods to detect tunnelluminance is accurate, convenient, and real-time, and there’s the very importantsignificance for the lighting environment controlling and energy saving.According to the standards and characteristics of tunnel illumination, analysis ofthe domestic and international advanced luminance detecting technology, in order toovercome the subjectivity and complexity of present luminance detection system. Thisarticle offer an embedded tunnel luminance online detection system based on imageprocessing technology and design the control scheme of dynamic image acquisitionand static image processing.Firstly, the selection of the core components and peripheral circuit design of eachfunctional module were designed through analzsis and experiment. The hardware ofminimum system, image acquisition, data cache, real-time display and datatransmission were designed after hardware debugging. The system diagram and PCBwere designed, the hardware platform was completed after PCB plate making andwelding.Secondly, the software implementation of each functional module was achievedon the hardware platform. The software implementation of image acquisition and image processing was achieved combined with gray conversion and filtering algorithmand the luminance of image was extracted.Finally, based on digital camera imaging method and the application ofphotometric principle, after the experiment of optical characteristics, the consistencyof luminance and value was achieved. The auto-exposure was proposed and itincreased the range of luminance detection effectively.Experiments show that the average luminance value of the scene can becalculated by the image processing and luminance detection algorithm and the resultscan be displayed and uploaded. The system meets the requirements of tunnelluminance detection and has certain stability and better practicability.